I don't have access to my machine right now, so I can't check exactly what worked for me. I didn't have the previous configuration either (the lutris scripts I used to install the games must have done this), so I just tried other options I had for runners. When I checked them they were all set on the last entry on the list.

I think for the 32-bit prefix error I had to choose a wine one instead (probably latest wine-GE).

For others that didn't show anything but had the gamemode error in logs, I switched to another proton version. I remembered being confused seeing two slightly differently worded entries that looked like latest proton GE, and using the other one worked.